PCDD Generation 1 Oral Liquid Acetaminophen Delivery Evaluation

Inclusion Criteria: Participants * Admitted to the participating orthopedic service for elective total shoulder replacement * Received a preoperative brachial plexus block * English speaking - as on-site study members are only fluent in English * Able to independently use the PCDD system and follow basic operating instructions Nurses * Registered nurse employed at Yale New Haven Hospital. * Provides clinical care to an enrolled study participant during the participant's hospitalization. * Willing and able to provide informed consent. Exclusion Criteria: Participants * Patient refusal to participate * Pregnancy: all child bearing age patients will receive a urine screening test on the day of surgery and this result will be documented in the EMR epic. This is an elective procedure and the surgery will almost always be cancelled in the case of positive pregnancy test. In the extremely rare event the care proceeds, we will exclude the patient from the study. Emergency surgery * Cognitive impairment preventing informed consent or independent use of the device * Chronic pain requiring ongoing pain management or home opioid use * Substance use disorder * Failed preoperative brachial plexus block, defined as significant postoperative pain in the PACU requiring early escalation of analgesic management Nurses * Declines or is unwilling to provide informed consent.